Modulating arrangement

ABSTRACT

239,872. Telefunken Ges. f³r Drahtlose Telegraphie. Sept. 12, 1924, [Convention date]. Addition to 239,534, [Class 38 (ii), Electric currents, Converting &amp;c.]. Magnetic modulating systems and apparatus. - A high-frequency conductor, comprising a non-magnetic core, coated or wound with a fine laver of iron, is used in a modulating system the characteristic feature of which is that both the highfrequency current to be modulated and the low-frequency or control current are both passed through the same conductor, the effective impedance of which is varied by the degree to which the iron coating is saturated by the magnetic field due to the control current. As shown in the Figure the high-frequency current is fed at the points k&lt;1&gt;, k&lt;2&gt; to a bifilar arrangement of conductors a1, a2, and a&lt;1&gt;1, a&lt;1&gt;2. The modulating current is applied at the points l&lt;1&gt;, l&lt;2&gt; which are preferably at equal high-frequency potentials. The conductor may be arranged in bifilar form as shown, or it may be zig-zag, or both, in order to lessen the magnetic flux not flowing in the iron.

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' gvwmtoz MENDEL OSNOS Patented Golf. HQ, WES.

U l S FTENT MENDEJL QSNOS, OF BERLIN, GERMANY, ASSIGNOR T GESELLSCHAFT FU'R DRAHTLOSE 'TELEGRAPHIE M. B. H. HALLESCHES, 0F BERLIN, GERMANY.

MODULAIING ARRANGEMENT.

The invention relates to an arrangement for communicating intelligence by varying the amplitude of a high frequency oscillation according to the desired intelligence.

This has become known in the art as modulation. v

More particularly, the invention relates to a modulating arrangement which employs a set of conductors suitably arranged, each conductor being made up of a strand of conducting mater1al, enveloped by a layer' of magnetic material.

An object of the invention is to provide an arrangement of the above kind which will 1.5 modulate faithfully, be cheap to make, and

reliable and eliicient in operation.

Other objects will be apparent from' the following description and claims when con sidered with the accompanying drawing, in

which,

Fig, 1 represents a circuit arrangement of the)1 conductor according to the invention, an

Fig. 2 is a cross-section of one form of conductor which may be used.

This application is an improvement over German patent application No. T-29,26 l, filed in Germary September 5, 1924-, which application was filed in the United States on October 20, 1925, under Serial Number In the parent patent a conductor for electric current adapted to high frequency work has been described which can advantageously be used as a choke coil, frequency changer, or the like. This conductor consists of a material possessing high conducting power for electricity, most preferably copper (in the form of a wire, rod or hig to frequency strand) which. is enveloped by a layer of ferro-magnetic material (especially iron), with, or, preferably, without, an intermediate layer of insulation. The conductor thus composed, with the end in view of reducing the magnetic flux (stray flux) not passing through iron, is arranged in bililar, zig-zag fashion, or else in a combination of bifilar and zig-zag fashions.

The present invention relates to the con trol (modulation) of the output of the said conductor, for the purpose of telegraphy, telephony, or the like. According to the invention, suchmodulation is efiected by supplying the current conductor in'question,

to apart from the high frequency current to be 63,618, and in Germany September 12, 1924.

controlled, With controlling currents which may be currents of loWer frequency, or else d1rect current.

Referring to the drawing, the conductors, a a,, a, and a, may each be made in any of the manners set forth above and in the parent application. However, for purposes of illustration, they are shown as made up of a core 1 of copper coated with a thin layer 2 of iron of the order of one-tenth of a millimeter in thickness. The conductors are arranged generally in the form of a Wheatstone bridge.

The high frequency current to be modulated flows by way of leads K K both through the branches a a arranged in bifilar fashion as well as the branches a a arranged in parallel to theformer and also arranged in bifilar fashion. The modulating currents are most preferably fed at points 1 and 1 which are at equal potential with reference to the high frequency currents to be modulated. However, this condition is not absolutely imperative; for

if the circuit passed by the modulating currents itself offers an adequately high impedance to the flow of the high frequency currents, or if for the same object a sufficiently large protective inductance coil 8 is inserted in the controlling circuit, the leads 1, and 1 may be connected at any convenient points of the high frequency conductors a,, a a and a The modulating currents themselves, by any of the well known methods of telegraphy or telephony, are varied or chopped (interrupted) either directly by the aid of a convenient device inserted in the circuit such as a key, telephone, or the like, or else indirectly by Way of an amplifier circuit.

Having described my invention, 1 am entitled to all modifications thereof, as fall fairly within its spirit and scope, as defined by the following claims:

1. In combination, aconductor having a magnetic material portion, a source ofhigh frequency to be modulated, a source of modulating current, and means for permitting current from both said sources to traverse said conductor, and influence the magnetic material portion thereof whereby said high frequency is modulated by said modulating current.

2. In combination, a conductor having a core of conducting material and a layer of magnetic material whereb the flux pro duced by current flowing t ru the conducting material traverses the said conductor only, a source of high frequency to be modulated, a source of modulating current, and means for permitting current from both said sourcesto traverse said conductor, whereby said high frequency is modulated by said modulating current.

3. In combination, a plurality of conductors, each having a core of conducting material and a layer of magnetic material whereby the flux produced by current flowing thru the conducting material traverses the patricular conductor only, said conductors being arranged in bifilar fashion with adjacent ends connected together, a source of high frequency to be modulated connected to said conductors intermediate the ends thereof, a source of modulating current connected to said adjacent ends.

4. In combination, a plurality of conductors, each having a core of conducting material and a layer of magnetic material whereby the flux produced by current flowing thru the conducting material traverses the particular conductor only, said conductors arranged to form a Wheatstone bridge, a first circuit containing a source of high frequency to be modulated connected across a pair of opposite corners of said bridge, a second circuit containing a source of modulating current connected across the other pair of diagonally opposite corners of said bridge.

5. In combination, a plurality of conductors, each having a core of conducting material and a layer of magnetic material whereby the flux produced by current flowing thru the conducting material traverses the particular conductor only, said conductors being arranged in pairs, each pair arranged bifilar fashion, the pairs being connected to form a Wheatstone bridge, a first circuit containing a source of high frequency to be modulated connected across a pair of opposite corners of said bridge, a second circuit containing a source of modulating current connected across the other pair of diagonally opposite corners of said bridge, and means for keeping highfrequency out of said second circuit.

6. in combination, a plurality of conductors, each having a core of conducting material and a layer of magnetic material whereby the flux produced by current flowing thru the conducting material traverses the particular conductor only, said conductors being arranged in pairs, each pair arranged bifilar fashion, the pairs being connected to form a l/Vheatstone bridge, a first circuit containing a source of the high frequency to be modulated connected across a pair of opposite. corners of said bridge, a second circuit containing a source of modulating current connected across the other pair of diagonally opposite corners of said bridge, said last-mentioned corners being at equal potential with respect to said first circuit.

MENDEL OSNOS. 

